Lithium batteries are widely applied to new energy vehicles, 3C products and energy storage batteries. In recent years, the demand for lithium batteries has been growing rapidly, driven by the rapid development of new energy vehicles. A lithium battery is mainly composed of the cathode material, anode material, electrolyte and separator. The separator is a key inner component whose performance determines the battery’s interface structure, internal resistance, etc. and directly affects the battery’s capacity, cycle and safety performance.

China’s lithium battery separator industry began in 2002, developed fast from 2009, and entered a high growth path in 2014 as driven by the prosperity of new energy vehicles. The industry’s market size grew from CNY 1.3 billion in 2013 to CNY 4.25 billion in 2017 at a growth rate over 300%. At present, lithium battery separators are mainly produced by dry process and wet process. Wet-processed separators surpass dry-processed ones in the size and distribution of apertures, mechanical strength and pyrocondensation. Wet processing is increasingly important and has become the direction for separator development as lithium batteries have higher energy density and quality.
The separator has the highest technological barrier among lithium battery materials. Domestic enterprises are proficient in dry process but poor at wet process due to the lack of technical talents. The wet processing of separators in China relies on imported production equipment featured by high prices and expensive debugging. Long certification cycle and stable supply chain are also the barriers against new entrants. As the demand continues to rise, the number of industry players is growing sharply, which leads to more fierce competition and lower product prices. The industry players are rapidly expanding their production capacity, hoping that mass production can help them gain an upper hand in the price competition and seize the market with higher production efficiency and more stable product quality. In 2017, the production capacity of lithium battery separators in China reached 2.7 billion sqm, which was excessive. It is expected to exceed 8 billion sqm in 2022, which will result in more overcapacity.
As domestic manufacturers make technological progress in the wet process, the industry localization will be accelerated and more market opportunities will be created. Domestic-made separators are seeing quality improvement with prices lower than their foreign counterparts. Therefore, lithium-ion battery enterprises prefer domestic-made separators that have higher cost performance. The government policies’ planning for and support to the new energy vehicle industry guarantee the demand growth in the lithium battery separator industry. It is expected that the market size of lithium batterie separators will exceed CNY 20 billion in 2022.